does come. And I'm not altogether sure that we're safe up here," he
added, as he looked down the sides of the hill to where the creek was
now rapidly becoming a raging torrent.

"Bless my hat-band!" gasped Mr. Damon. "You--you are getting on my
nerves!"

"I don't want to be a calamity howler," went on the foreman; "but we've
got to face this thing. We'd better get ready to vamoose if Tom Swift
doesn't reach here in time to fire that shot--and he doesn't seem to be
in sight."

Once more Ned swept the sky with his glasses. The roar of the water
below them could be plainly heard now.

"I wish I could get hold of that rascally German," muttered the
foreman. "I'd give him more than a piece of my mind. It will be his
fault if the town is destroyed, for Tom's plan would have saved it. I
wonder who he can be, anyhow?"

"Some spy," declared Ned. "We've been having trouble right along, you
know, and this is part of the game. I have some suspicions, but Tom
doesn't agree with me. Certainly the fellow, whatever his object, has
made trouble enough this time."

"I should say so," agreed the foreman.

"Look, Ned!" cried Mr. Damon. "Is that a bird; or is it Tom?" and he
pointed to a speck in the sky. Ned quickly focused his glasses on it.

"It's Tom!" he cried a second later. "It's Tom in the Humming Bird!"

"Thank Heaven for that!" exclaimed Mr. Damon, fervently, forgetting to
bless anything on this occasion. "If only he can get here in time!"

"He's driving her to the limit!" cried Ned, still watching his chum
through the glass. "He's coming!"

"He'll need to," murmured the foreman, grimly. "That dam can't last ten
minutes more. Look at the people fleeing from the valley!"

He pointed to the north, and a confused mass of small black
objects--men, women and children, doubtless, who had lingered in spite
of the other warning--could be seen clambering up the sides of the
valley.

"Is everything ready at the gun?" asked Mr. Damon.

"Everything," answered Ned, whom Tom had instructed in all the
essentials. "As soon as he lands we'll jam in the powder, and fire the
shot."

"I hope he doesn't land too hard, with all that explosive on board,"
murmured the foreman.

"Bless my checkerboard!" cried Mr. Damon. "Don't suggest such a thing."

"I guess we can trust Tom," spoke Ned.

They looked up. The distant throb of the monoplane's motor could now be
heard above the roar of the swollen waters. Tom could be seen in his
se